1,284 Exoplanets Found: NASA's Kepler Space Telescope Discovery in Pictures

Kepler vs. Ground-Based Telescopes

NASA Ames/W. Stenzel; Princeton University/T. Morton

Verifying Kepler's planet finds is a huge challenge because the space telescope can see fainter stars than those typically targeted by ground-based telescopes. This NASA chart shows that the candidate planets of Kepler (shown in orange) tend to be smaller and orbit fainter stars than those observed by ground-based telescopes (in blue) using the same transit method.

Is It Really a Planet?

NASA Ames/W. Stenzel; Princeton University/T. Morton

NASA explains Kepler's new validation method as thus: "A new statistical validation technique enables researchers to quantify the probability that any given candidate signal is in fact caused by a planet, without requiring any follow-up observations. This technique uses two different kinds of simulations-- both simulations of the detailed shapes of transit signals caused by both planets and objects, such as a star, masquerading as planets (left diagram), and also simulations of how common imposters are expected to be in the Milky Way galaxy (right diagram). Combining these two different kinds of information gives scientists a reliability score between zero and one for each candidate. Candidates with reliability greater than 99 percent are call 'validated planets.'"

Kepler Space Telescope: 2009-2017


NASA's initial mission for the Kepler Space Telescope ended in May 2013, when the second of four reaction wheels failed and limited the telescope's vital precision pointing capability. In May 2014, NASA approved a follow-up K2 mission, which runs through September 2017. The k2 mission aims Kepler at stars along the plane of Earth's orbit (the ecliptic).

The Future of Exoplanet Discovery

NASA Ames/N. Batalha and W. Stenzel

The Kepler Space Telescope is just one in a long line of missions and projects aimed at finding planets around distant stars. Future space telescopes and new techniques promise to push the limits of astronomical discovery.

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Tariq Malik

Tariq is the Editor-in-Chief of Space.com and joined the team in 2001, first as an intern and staff writer, and later as an editor. He covers human spaceflight, exploration and space science, as well as skywatching and entertainment. He became Space.com's Managing Editor in 2009 and Editor-in-Chief in 2019. Before joining Space.com, Tariq was a staff reporter for The Los Angeles Times covering education and city beats in La Habra, Fullerton and Huntington Beach. In October 2022, Tariq received the Harry Kolcum Award for excellence in space reporting from the National Space Club Florida Committee. He is also an Eagle Scout (yes, he has the Space Exploration merit badge) and went to Space Camp four times as a kid and a fifth time as an adult. He has journalism degrees from the University of Southern California and New York University. You can find Tariq at Space.com and as the co-host to the This Week In Space podcast with space historian Rod Pyle on the TWiT network. To see his latest project, you can follow Tariq on Twitter @tariqjmalik.